The difficulties inherent in removing and maneuvering manhole covers is both well-known in practice and well-documented in patent literature. The realities of modern automobiles and transportation thoroughfares have long dictated the necessity for sturdy steel and iron access coverings most traditionally associated with urban drainage tunnels. More recently, many public utility companies have also taken to underground routing for their various service conduits, be they gas, electric, cable, or telephone. Although underground tunnels for these sorts of utility services are sometimes located away from automobile thoroughfares, the standard steel or cast iron manhole cover appears well entrenched for use in these and other varied applications. Accordingly, the injury risks associated with removing and replacing manhole covers remain common to many people in the modern workforce.
Prior art devices that have attempted to address the problems inherent in removing, moving, and replacing manhole covers and storm sewer grates are of two general types. The first type consists of devices that rely upon mechanical or geometric interfaces with the manhole cover. Since the detail, location, and design of holes, slots, cleats, clevises, and the like vary from one manhole cover to another, devices relying upon purely mechanical interfaces necessarily require a host of adapters and other accessories that enable one device to be of universal use for all manhole covers. Thus, while devices of this type may succeed in preventing injury, they are complex, often occupying a workman's valuable time with detailed and tedious efforts to select, set up, and correctly use the necessary adapters for any particular manhole cover, provided that he has not lost or misplaced the requisite parts along the way.
The second general type of prior art device consists of those devices that are so over-engineered and bloated with detail that many approach a size and weight rivaling that of the average manhole cover. Such devices employ one or more of electromagnets, pulleys, gears, and hydraulics to the point that such “solutions” to the original problems posed by manhole covers are problematic in their own right. These devices have either a superfluity of moving parts or are of such a size that a workman risks injury in the process of loading or unloading the device from his vehicle.
It is therefore desirable to have a simple, portable device that eliminates the risk of injury in the processes of removing, moving, and replacing manhole covers that is at once versatile and both lightweight and compact. The present invention addresses itself to these concerns.